And a TLD shouldn’t be so easy to mistake for one of the most recognisable filetypes ever, yet here we are. Well made apps discern between a zip file and a zip web address without issue. The problem, as usual, is in the human element:

• Register a zip domain called holidayphotos2025.zip, 2025ProductData.zip or whatever hook you’re going for.
• Serve up whatever malicious garbage you like on it. Spoofed login pages, browser exploits, anything goes.
• Email it out from an already compromised account to all account contacts, removing the https component of the link text. Bonus points for imitating how an attachment would look in the target email client.
• Watch the clicks roll in as people try to open the ‘attachment’.

Having .zip in the string and in the link visible on hover could be all that is needed to ‘sell’ it to a user that makes a cursory glance before clicking - nevermind the ones that just click anyway. Plenty of folk have fallen for more obvious traps than that, so it’s a winner for a bad actor. Any trick that lends legitimacy to a scam increases the chance of success. Users savvy enough to check but not enough to spot the discrepancy may also have more data interesting to an attacker.

Blocking .zip TLDs wholesale at DNS level kills this even if the first and hardest hurdle (getting the user to click) is cleared. I’ll concede that it is an edge case in the grand scheme of things, but why leave the hole open when it is so easily plugged?